1. Technical Field
The invention relates to the field of ductwork or pipe interior cleaning systems and more particularly to an umbrella or parachute type cleaning plug apparatus for cleaning the interior of such ducts or pipes.
2. Background Art
Cleaning plugs or kites are used generally by cleaners of waste collection systems, air duct work, and the like for loosening solid materials, such as dirt, stone, mud and other debris, from the interior walls of pipes or ducts.
Kites and other types of cleaning plugs are well known in the pipe cleaning art. For example, U.S. Pat. Nos. 5,336,333; 5,341,539; 5,068,940; 1,035,994; 2,481,152; 2,508,659; 4,141,753; and, 5,364,473 teach various embodiments of cleaning plugs or kites for use in the cleaning of the interior of pipes.
A cleaning plug or kite may be placed in the interior either of a pipe, such as a sewer line, or a duct, such as an air handling or air conditioning system in a building. The fluid flowing in the pipe is blocked by the bag device thereby expanding the first end of the kite. Generally, the first end of the kite is sized such that when the kite is fully expanded the first end approximates the size or diameter of the interior of the pipe. The fluid flow is then either totally stopped or a pressurized stream may flow between the outer edge of the kite and the interior wall of the pipe. Alternatively, an opening may be formed in the apex of the kite or bag to permit fluid flow therethrough. Such flow through the formed opening would increase the pressure of the resulting stream exiting through the kite as a result of the fluid flowing through a reduced cross-sectional area. Finally, the pulling of the rigging securing the kite against the fluid pressure in the pipe often creates pockets or folds in the outer edge of the first end of the kite. Pressurized fluid jets or streams then can escape between the folds and the pipe""s interior wall.
The relatively high pressure water or fluid is used to flush or wash undesired solid debris downstream through the pipe system.
Check valves are also well known in the art pertaining to valve structures. A check valves is a valve that permits flow in one direction only, that is to prevent backflow. Check valves have been used in past wastewater systems, such as in sluice gates. Known types of check valves include dual plate hinged and also all-rubber construction that seals and closes. An exemplary offeror of metal-hinged check valves is Techno Corporation of Millbury, Mass. (www.technovalve.com). Other check valve offerors are available and can be found readily through searching for check valves on the Internet.
However, such a known check valve has not been used in the field of cleaning plugs or kites.
While the above-cited references introduce and disclose a number of noteworthy advances and technological improvements within the art, none completely fulfills the specific objectives achieved by this invention.
In accordance with the present invention, a cleaning plug is adaptable to be placed within an interior passageway of a tube or duct within a tubular system, such as a sewer or air conditioning duct. The plug includes a bag or generally conically shaped element that has a first end and an opposite second end. The first end has a width selected to fit within the interior passageway of the tube. The second end has a width less than the width of the first end. A securing system or rigging is connected to the conical element in proximity to the first end for controllably securing the bag or conical element in desired positions within the interior passageway of the tube or duct.
A valve assembly is mounted with the second end of the conical element. The valve assembly has a normally closed position and an open state. The normally closed state prevents appreciable fluid flow therethrough. The open position permits fluid flow through the valve assembly upon sensing of a flow pressure therethrough greater than a minimum selected pressure value.
The valve assembly acts as a safety valve to prevent xe2x80x9cblow-outxe2x80x9d of the bag and also functions to provide a cleaning jet of fluid to flush undesired debris downstream of the kite.
These and other objects, advantages and features of this invention will b e apparent from the following description taken with reference to the accompanying drawings, wherein is shown the preferred embodiments of the invention.